1. Technical Field
The present invention relates to a liquid ejecting head and liquid ejecting apparatus that eject liquid. More particularly, it relates to an ink jet recording head and ink jet recording apparatus that discharge ink as a liquid.
2. Related Art
An ink jet recording head is structured such that a vibration plate forms part of pressure generating chambers that are in communication with associated nozzle orifices, and the vibration plate is deformed by piezoelectric elements to apply pressure to ink contained in the pressure generating chambers, so that ink droplets are discharged from the nozzle orifices. Then, an ink jet recording head that utilizes flexural deformation of piezoelectric elements, each having a lower electrode, a piezoelectric layer and an upper electrode, is in practical use.
Some of the ink jet recording heads are formed of drive vibrators (piezoelectric elements), which are supplied with a drive signal to deform, and dummy vibrators that are not supplied with a drive signal, and then a film wiring substrate is electrically connected to each electrode of the drive vibrator, which is, for example, described in JP-A-2003-291337. By heating solder provided on the wiring layers, the upper electrodes of the piezoelectric elements are electrically connected to the associated wiring layers of the wiring substrate.
When the upper electrodes of the piezoelectric elements are connected to the associated wiring layers of the wiring substrate through solder, flux that prevents generation of oxide by lowering the melting point of solder is generally used. However, because the flux is applied on the side of the wiring substrate on which solder is provided, redundant flux flows out to the side of the piezoelectric elements when the upper electrodes and the wiring layers are connected. This causes problems in which leakage current and/or migration occur between the adjacent piezoelectric elements, resulting in a decrease in relative displacement characteristics and deterioration of moisture resistance of the piezoelectric elements. Specifically, when a decrease in relative displacement occurs in the piezoelectric elements located at the opposite ends in a direction in which the piezoelectric elements are arranged in parallel with each other, stable ink discharge characteristics cannot be attained.
Note that these problems not only exist in ink jet recording heads that discharge ink but also exist in liquid ejecting heads that eject liquid other than ink.